Re-reading the first section, I realized it is about exp. (When I read it yesterday, I didn't know about uppercase macros, so I turned on the second link, and from rfc4408 to rfc3986 to learn what's an "uric".) What about changing the section title to something like

> It's not limited to %{L} vs. %{l}, e.g., HELO %{H} can also be odd > if it's used in the URL of an explanation.

Won't it come in its '--'-encoded form anyway?

> [ISP hints] >> Many use "_spf" rather than "dummy". Does it make sense to follow >> that trend? > > Sure, here I didn't want to go into details about underscores in > DNS names, there's a separate FAQ entry for this: > http://www.openspf.org/FAQ/Underscore_in_DNS> > If readers think that _spf is required it won't cause havoc, but > implementors should not get odd ideas, any <target-name> is okay.

It could be clarified in the text that it doesn't have to be "_spf". There are chances that the string exemplified is pasted in the zone file "as is" (luckily, rfc2606 has been issued early enough...)

[.[. Personally I think exp= and %{l} are some of the two worst ideas in SPF, exists: and SOFTFAIL are also dubious. Considering how many folks get mx wrong, while Doug invents DDoS scenarios based on mx and %{l}, I'm ready to add mx to the list, as long as RMX stays in the credits... ;-) ]]

> What about changing the section title to something like > == '''Why'''-service URL in Explanation modifiers Which section, the remark in FAQ/I18N ? It can get a link to Modifier/exp, and Modifier/exp can explain the fine print of upper case macros with an example.

>> HELO %{H} can also be odd if it's used in the URL >> of an explanation. > Won't it come in its '--'-encoded form anyway?

Is that about punycode xn--labels ? What I meant was a crappy HELO oem&computer - clear SMTP syntax error, but if the receiver accepted it, and later tries to report a FAIL with an explanation including %{H}, then it is at least transformed to oem%26computer

[dummy vs. _spf labels] > It could be clarified in the text that it doesn't > have to be "_spf". There are chances that the string > exemplified is pasted in the zone file "as is"

Which string, dummy.your.domain.example ? If an ISP tries to use that as is it's no ISP, problem solved ;-)

My recollection is that the internationalization work was going on in parallel to the design of SPF and we conciously decided to ignore it. If there are some complexities that aren't well dealt with it should not suprise anyone.

> [.[. Personally I think exp= and %{l} are some of the > two worst ideas in SPF, exists: and SOFTFAIL are > also dubious. Considering how many folks get mx > wrong, while Doug invents DDoS scenarios based > on mx and %{l}, I'm ready to add mx to the list, > as long as RMX stays in the credits... ;-) ]]

I may agree about the cosmetic nature of exp= and %{l}, but exists: is not dubious at all, as it enables complete control over authorized senders. For example, one could configure a server so as to automatically add a remote client's IP to various DNS records upon IP assignment, possibly including A, MX, and PTR besides accomplishing the exist: mechanism. That would allow to go along with the wishes of those folks who run an MTA on their laptops...

>> What about changing the section title to something like >> == '''Why'''-service URL in Explanation modifiers > > Which section, the remark in FAQ/I18N ?

I meant "SPF Internationalization". Actually both words in the current section title (the 2nd one in its abbreviated form) appear already in the titles hierarchically above that section, i.e. page and site.

> It can get > a link to Modifier/exp, and Modifier/exp can explain > the fine print of upper case macros with an example.

Great!

> [dummy vs. _spf labels] >> It could be clarified in the text that it doesn't >> have to be "_spf". There are chances that the string >> exemplified is pasted in the zone file "as is" > > Which string, dummy.your.domain.example ? If an ISP > tries to use that as is it's no ISP, problem solved ;-)

Hmm... I regret I just canceled the quoting about oem&computer, otherwise I could mention that as a counter example ;-)